1. Field of the Invention
The present invention relates to a bonding material that joins a susceptor for a semiconductor manufacturing device, such as an electrostatic chuck or an electrostatic chuck equipped with a heater, to a cooling board, and also relates to a semiconductor supporting device having a susceptor for a semiconductor manufacturing device and a cooling board joined with the bonding material.
2. Description of the Related Art
Conventionally, liquid silicone rubber, a metal layer containing indium (In), or an organic adhesive agent such as an acrylic adhesive agent or an epoxylic adhesive agent is used for joining a susceptor for a semiconductor manufacturing device to a cooling board which controls the temperature of a Si wafer to be held on the susceptor (see Japanese Patent Application Laid-open Nos. H4-287344, H3-3249, and 2002-231797).
However, when liquid silicone rubber is used for joining the susceptor to the cooling board, the susceptor suffers warping because the volume of the liquid silicone rubber shrinks by curing. As a result, the flatness of the susceptor may decrease. Alternatively, when an In-containing metal layer is used, a process for manufacturing a semiconductor device may be contaminated with In. On the other hand, when an organic adhesive agent is used, the heat resistance of the composite is poor since the heat resisting temperature of the organic adhesive agent is as low as about 100° C.